A quartz crystal oscillator is very precise and stable, and has been widely used in various oscillating circuits for a color TV set, a computer and a remote controller, as well as used in a communication system as a frequency generator, to generate a clock signal for a data processing device and to provide a reference signal for a particular system.
So far, an Oven Controlled Crystal Oscillator (OCXO) is a crystal oscillator with the best frequency stability and precision and is excellent in performances such as aging rate, temperature stability, long-term stability and short-term stability, and hence has been widely used in various fields as a precise time-frequency signal source.
As shown in FIG. 1, in an existing Oven Controlled Crystal Oscillator, a crystal resonator 20 and a heating device 30 for direct heating are mounted on both sides of a Printed Circuit Board (PCB) 10, respectively. Such temperature control manner is poor in temperature control precision in that if the ambient temperature changes, a part of the crystal resonator 20 that is farthest from the heating source is likely to be influenced by the ambient temperature change.
In another temperature control manner as shown in FIG. 2, a crystal resonator 20 is mounted on an inner PCB 10 accommodated in a metallic thermal conductive chamber 40, and a heating device 30 connected with and powered by an outer PCB 50 is arranged on the external side of the metallic thermal conductive chamber 40. However, this manner introduces additionally the metallic thermal conductive chamber and the outer PCB for the purpose of the heating conducted indirectly via the metallic thermal conductive chamber, so that both the component volume and power consumption is significantly increased, and both costs and manufacturing process complexity is increased accordingly.
Therefore, there is an urgent need for an OCXO with a small volume and a high temperature control precision.